Firefighters are often confronted with the need to enter an area which, because of an existing or previous fire, is breathable air-deprived to the point where neither a firefighter nor an internal combustion driven appliance, such as a chainsaw or cutter, can function to full effect. While it is known to supply the firefighter with a personal breathing apparatus fed by a tank of compressed air, a tool such as a chain saw or circular saw, when needed, is left to run at reduced horsepower, if at all, on whatever air or oxygen is left in the area that the firefighter has entered.
Appliances such as chainsaws and cutters are often needed to clear debris or provide either or both of ingress and egress to/from an active area for one or more firefighters. A poorly functioning or non-functioning appliance or tool may be a significant liability to the firefighter's effectiveness and/or safety.